1. Technical Field
This invention consists of thermal insulation for pipes of steel of a drill pipe riser, also denominated as DPR, for the exploitation of petroleum in subsea wells.
2. History of Related Art
As it is generally known, a drill pipe riser is made up of several lengths of pipes threaded together at their respective ends, to be used to drill an oil well, as well as for long-term production test of wells (lasting five to nine months) in order to measure the flowrate of that well or if the well is economically viable. The long-term production test also allows the pre-production of the well.
After the conclusion of the tests, the drill pipe riser is removed and the final flexible pipe risers are installed.
The pipes of the drill pipe riser are made of steel and, considering the low temperatures at great depths, said pipes must be thermally insulated, in order to prevent heat transfer from the petroleum to the seawater during its passage from the sea bottom to the surface. If there is no thermal insulation, the petroleum becomes very viscous substantially reducing its flow rate.